mcmahan



G. M. MCMAHAN;

Self-@losing Door.

Patented Apr. 14, 186%.

V Nr 76.790.

Fig. 2.

- Witnesses.

MPETEIKS. PHofmLlTHoGRAPHER, wAsHmGfoN, o 0.

M. MCMHAN, 0F MOUNT STERLING, KENTUCKY.

Letters Patent No.v 76,790, datedflprzl 14, 1868.

IMPROVEMBN T IN DOORS.

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T0 ALL WHOM IT MAY CONGERN Be it known that I, G. M. McMAHAN, of Mount Sterling, in the county of Montgomery, and State of Kentucky, have invented a new and improved Self-Acting Door; and I do hereby declare the following to be' a full, clear, and exact description of the same, sufficient to enable those skilled in the Vart to which my invention appertains to make usc of it, reference being had to the accompanying drawings, forming part-of this specication, in which Figure 1 is a side elevation, and

Figure 2 a plan of my invention.

This invention is a door for houses, so constructed and operating, that, while at other times it remains closed, it will automatically open upon the approach of any person who desires to pass through.

In the drawings, A represents the partition-wall, and B the floor of the house, and D D doors operating automatically, as above described. The mechanism by which they are so operatedwill be understood by the following explanation.

Each door is opened and closed by the action of au upright rod, C, which rocks or partially rotates on its vertical axis, the top of the rod being connected with the door by an arm, c. The rodtcrminates at its lower v end, under the oor,in a spur-wheel, w, which gears into a segment, s, attached to a rocking-rod, R. This rod is provided near its centre with a horizontal arm -or arms, a a, underneath whicli is a spring, m, acting upwards againstrthe arms, and keeping them in a' horizontal position, and thereby, through the instrumentality of the segment, spur-wheel, and rod C, keeping the doors closed., I

The doors being thus held closed by the spring m, any force which overcomes the spring, and moves the arms a a downward, will actuate thc segment and rod R inthe opposite direction to that in which they are actuated by thc spring, and will open the doors. I

4Having thus constructed and arranged the machinery, by which the doors can be opened or closed et pleasure, by power applied under the door, I cut a large hole through the door, on either side of the door, and till it with a horizontal platform, B', the upper surface of which is level with the floor. This platform is so c onstructed that the weight of a person stepping upon it will depress it, until a pin, p, on its under side, comes in contact with one of the arms a a, presses them down, and opens the door for the person to pass through.

In order to hold the platform so that it will ordinarily be level with the surrounding floor, yet capable of being depressed and of rising again, I support and 4ggide it at its four corners by means of tubularsupports, e e, enclosing the upper end of and sliding up and vdown upon short upright posts, n n; both the posts, and the tubes which work over them, being surrounded by a stout spiral spring, u u, which presses up against theA platform, and holds it in position.

From the bottom of these posts spring arched beams, I I, which cross each other under the centre of the platform. The apparatus is so arranged that the pimp, comes at the intersection of these bcarnswith each other, and passes through a vertical h'ole in them at that point. The'bearns thus contribute to steady and guide the platform in its motion up and-down, vas well as to furnish a rest for it when depressed.

In iig. 1,' the platform is represented as depressed, and resting upon the arched beams. The wood of the platform may be protected, where it cornes in contact with the beams, by an iron plate, z'. y

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The combination of the door D, rods C Rfg'earing w s, arm-a,.and spring m, with the platform B', posts n n, hollow supports e e, springs u et, arched beams I I, and pimp, when the said parts are constructed and arranged so as to operate in connection with each other, substantially in the manner and `for `the purposes set forth.

Gr. M. McMAHA-N.

Witnesses:

J. C. WELLS, R. M. JOHNSON. 

